i just finished putting up my yakima load warrior rack with custom brackets i fabbed myself. it holds extremely tight and is strong enough to hold me jerking on them with out moving at all. i started out with a two foot section of 4 in. channel iron, cut it in half length wise and welded the two pieces together,i cut it into 3 in. long pieces and drilled three holes in the top, (the end that protrudes the furthest) i welded 3/8 in. nuts to the holes in the outer edges. i had to cut the bottom edge down to where i could slide it under the edges of the factory rails on the roof and i belive i cut it down to about 3/8 in. to 1/2 in. i would some sort of padding on the bottom of the edges in the front. i ran 3/8 in. diameter bolts through the brackets after i slid them under the factory rails and clamped them down. they should fit in the grooves.i took a length of 1 in. square tubing to use as cross bars.drill holes in the bars in correct location to drop a bolt through the brackets tighten it and put the rack on